Translucent dust cap and associated method for testing the continuity of an optical fiber jumper

ABSTRACT

A dust cap is provided that includes a translucent end member that permits optical communication while the dust cap remains mounted upon a ferrule. The dust cap includes a sleeve having an open first end and an opposed second end that is closed by the translucent end member. The end member can also include a lens to facilitate optical communication. A medial portion of the sleeve can also define an internal chamfer that extends radially inward for engaging the ferrule such that the front face of the ferrule is spaced from the second end of the sleeve, thereby preventing contaminants from being transferred from the second end of the sleeve to the polished front face of the ferrule. The dust cap can also define a groove extending lengthwise through only a portion of the sleeve, i.e., from the first end of the sleeve to a medial portion of the sleeve. The groove therefore permits air to vent from the bore while the dust cap is being mounted upon the ferrule, while isolating the front face of the ferrule from the external environment once the dust cap has been fully mounted, thereby protecting the polished front face of the ferrule from contaminants that may enter the groove. A method is also provided for testing the continuity of an optical fiber jumper that utilizes optical communications conducted through the translucent dust caps.

FIELD OF THE INVENTION

The present invention relates generally to dust caps that are mountedupon ferrules to protect the front faces of the ferrules fromcontaminants and, more particularly, relates to translucent dust capsand an associated method for testing the continuity of an optical fiberjumper that has translucent dust caps mounted upon the opposed endsthereof.

BACKGROUND OF THE INVENTION

Once a fiber optic connector has been mounted upon the end portion of anoptical fiber and the front face of the ferrule of the fiber opticconnector has been polished, a dust cap is commonly mounted upon theferrule. The dust cap protects the polished front face of the ferrulefrom contaminants or other debris that would otherwise degrade theperformance of the resulting optical system. For example, fiber opticconnectors are generally mounted upon the opposed ends of an opticalfiber jumper during the manufacturing process. In order to protect thefront faces of the ferrules of the fiber optic connectors fromcontaminants and other debris following the polishing of the front facesof the ferrules, dust caps are typically mounted upon the ferrules priorto packaging and shipping the optical fiber jumper.

Conventional dust caps are fabricated from an opaque plastic material,such as a low density polyethylene material. This material isadvantageous in that it is relatively inexpensive. Unfortunately,conventional dust caps tend to bleed off a plasticizer that can betransferred to and contaminate the front face of the ferrule. Aconventional dust cap includes a sleeve that defines a bore extendinglengthwise between opposed first and second ends. The first end of aconventional dust cap is open to permit the ferrule to be inserted intothe bore. In contrast, the second end of the dust cap is closed. Aconventional dust cap is generally designed to be mounted upon a ferruleby inserting the front face of the ferrule through the open first end ofthe dust cap and into the bore and thereafter slideably advancing thedust cap upon the ferrule. The slideable advancement of the dust captypically continues until the first end of the dust cap contacts aninwardly extending flange of the inner housing of the fiber opticconnector. A conventional dust cap therefore defines a straight borehaving a constant diameter that equals or slightly exceeds the diameterof the ferrule and that is slightly longer than the length of theferrule that is anticipated to be inserted into the dust cap. As such,the front face of the ferrule does not generally contact the closedsecond end of the dust cap and thereby avoids picking up contaminants orother debris carried by the second end of the dust cap.

A dust cap is typically molded about a pin that defines the bore. Uponpulling the pin out of the dust cap following the molding process,flakes of material may be pulled outwardly from the second end of thedust cap so as to extend into the bore. In some instances, these flakesof material contact the front face of the ferrule once the dust cap ismounted thereupon. In instances in which flakes of material from thesecond end of the dust cap do contact the front face of the ferrule,contaminants or other debris can be transferred to the front face of theferrule even though the front face of the ferrule is otherwise spacedslightly from the second end of the dust cap.

In order to facilitate the mounting of a dust cap upon a ferrule, aconventional dust cap also typically defines a groove that opens intothe bore and that extends lengthwise from the first end of the dust capthrough the entire bore. As will be apparent, the groove facilitates themounting of a dust cap upon a ferrule by permitting air that wouldotherwise be trapped within the bore between the front face of theferrule and the second end of the dust cap to escape. Since the grooveruns the length of the bore, however, contaminants and other debris canalso enter the bore via the groove even after the dust cap has beenfully mounted upon the ferrule. These contaminants and other debris thatenter via the groove may disadvantageously be deposited upon the frontface of the ferrule.

The removal of the dust cap from a ferrule will obviously expose thefront face of the ferrule to contaminants and other debris. Moreover,the removal of the dust cap from the ferrule will also electricallycharge the ferrule such that contaminants and other debris areelectrically attracted to the ferrule. As such, it is desirable for thedust cap to remain on the ferrule from immediately following thepolishing of the front face of the ferrule to some time immediatelypreceding the interconnection of the fiber optic connector duringinstallation of the optical fiber. Unfortunately, a dust cap musttypically be removed at least once after its initial mounting upon theferrule following the polishing of the front face of the ferrule andprior to its ultimate removal from the ferrule in the course ofinstalling the optical fiber.

For example, during a conventional manufacturing process in which fiberoptic connectors are mounted upon the end portions of one or moreoptical fibers, such as during the fabrication of optical fiber jumpers,the front face of the ferrule is typically polished and the opticalfiber jumper is then subjected to performance tests, including teststhat measure the insertion loss and the back reflection prior tomounting a dust cap upon the ferrule. After mounting the dust cap uponthe ferrule, an outer shroud is assembled to the inner housing and aboot is inserted into the rear of the outer shroud in order to completethe assembly of the fiber optic connector.

Even though performance tests were conducted following the polishing ofthe front faces of the ferrules, optical fiber jumpers must generally betested again for optical continuity immediately prior to being packagedand shipped to a customer in order to minimize the number of defectiveoptical fiber jumpers that are delivered. In this regard, a continuitytest is generally desirable since the assembly of the outer shroud andthe boot following the prior performance testing and the mounting of thedust cap upon the ferrule could have broken an optical fiber orotherwise impaired the continuity of the optical fiber jumper. Theopaque dust caps must therefore be removed from both ends of the opticalfiber jumper to permit the continuity of the optical fiber jumper to betested. If the optical fiber jumper passes the continuity test, the dustcaps are then remounted upon the respective ferrules prior to packagingand shipping the optical fiber jumper to a customer. During therelatively brief time in which the dust caps are removed from therespective ferrules, however, contaminants and other debris may bedeposited upon the front faces of the ferrules, especially in light ofthe, electrical charge that may be imparted to the ferrules uponremoving the dust caps therefrom. Thus, the resulting system performancemay be degraded once the optical fiber jumper is installed due to thecontaminants and other debris that are deposited upon the front faces ofthe ferrules.

SUMMARY OF THE INVENTION

A dust cap is therefore provided that addresses these and othershortcomings of conventional dust caps in order to further reduce theopportunity for contaminants and other debris to be deposited upon thepolished front face of a ferrule. The dust cap can be constructed suchthat at least the closed end is translucent in order to permit opticalcommunication with an optical fiber upon which the ferrule is mountedwhile the dust cap remains mounted upon the ferrule, such as duringcontinuity testing. The dust cap can also include an internal chamferthat extends radially inward for engaging the ferrule in order to insurethat the front face of the ferrule is adequately spaced from the closedend of the dust cap, thereby preventing the transfer of contaminants orother debris from the closed end of the dust cap to the polished frontface of the ferrule. In addition, a dust cap can define a groove that isdesigned to vent air during the mounting of the dust cap upon a ferrule,but that extends only to a medial portion of the dust cap in order toprevent contaminants or other debris from passing through the groove andbeing deposited upon the front face of the ferrule once the dust cap hasbeen fully mounted upon the ferrule. A method for checking thecontinuity of an optical fiber jumper is also provided in which thetranslucent dust caps remain mounted upon the respective ferrules whilelight is introduced into one end of the optical fiber jumper and lightis emitted from and monitored at the other end of the optical fiberjumper. Accordingly, the dust cap of the present inventionadvantageously permits the continuity of an optical fiber jumper orother types of optical fibers to be confirmed without having to removethe dust caps from the respective ferrules that would subject the frontfaces of the ferrules to contaminants or other debris and subsequentlyimpair the system performance once the optical fiber jumper wasinstalled.

The dust cap includes a sleeve extending lengthwise between opposedfirst and second ends. The sleeve defines a lengthwise extending borethat opens through the first end for receiving at least a portion of theferrule. The dust cap also includes an end member for closing the secondend of the sleeve. In one advantageous embodiment, at least the endmember is translucent for permitting optical communication with theoptical fiber upon which the ferrule is mounted while the dust capremains mounted upon the ferrule. Typically, the sleeve and the endmember are integral such that the sleeve is also translucent. Forexample, both the sleeve and the end member can be formed of nylon.According to this embodiment, the end member can also include a lens.For example, the lens can include an outer planoconvex lens proximatethe outer surface of the end member. Additionally, the lens can includean inner lens proximate the inner surface of the end member. In eitherinstance, the lens serves to focus incident optical signals upon theoptical fiber upon which the ferrule is mounted and to expand opticalsignals emitted by the optical fiber in order to facilitate opticalcommunication therewith.

In one embodiment, a medial portion of the sleeve defines an internalchamfer that extends radially inward for engaging the ferrule such thatthe front face of the ferrule is spaced from the second end of thesleeve. Thus, contaminants and other debris will not be transferred fromthe closed second end of the sleeve to the polished front face of theferrule. In this embodiment, the portion of the bore extending betweenthe first end of the sleeve and the internal chamfer generally has alarger diameter than the portion of the bore extending between theinternal chamfer and the second end of the sleeve.

The dust cap of one embodiment of the present invention also defines agroove opening into the bore and extending lengthwise through only aportion of the sleeve. In this regard, the sleeve defines the groove toextend only from the first end of the sleeve to a medial portion of thesleeve. Preferably, the medial portion of the sleeve to which the grooveextends is selected such that the front face of the ferrule will bepositioned between the medial portion of the sleeve and the second endof the sleeve. In one embodiment, for example, the sleeve defines thegroove to extend only from the first end of the sleeve to the medialportion of the sleeve that defines the internal chamfer. Thus, eventhough the groove permits air to vent from the bore while the dust capis being mounted upon the ferrule, the front face of the ferrule will beisolated from the groove and, in turn, from the external environmentonce the dust cap has been fully mounted upon the ferrule, therebyprotecting the polished front face of the ferrule from contaminants andother debris that may enter the groove.

A method is also provided according to one embodiment of the presentinvention for testing the continuity of an optical fiber jumper. In thisregard, the optical fiber jumper includes at least one optical fiber,first and second fiber optic connectors including respective ferrulesmounted upon opposed ends of the at least one optical fiber and at leastone dust cap having a translucent end member mounted upon a respectiveferrule. According to this method, light is introduced into one end ofthe optical fiber and the light emitted by the other end of the at leastone optical fiber is monitored to test the continuity of the opticalfiber jumper while the at least one dust cap remains mounted upon therespective ferrule. More commonly, the optical fiber jumper includesfirst and second dust caps with translucent end members mounted upon theferrules of the first and second fiber optic connectors, respectively.In one advantageous embodiment, the end member of each dust cap includesa lens such that introducing light into one end of the least one opticalfiber also includes focusing light into one end of the at least oneoptical fiber. Conversely, monitoring the emitted light also includesexpanding the light emitted by the other end of the at least one opticalfiber. As such, the continuity of an optical fiber jumper can be checkedwithout having to remove the dust caps from the respective ferrules thatwould disadvantageously expose the polished front faces of the ferrulesto contaminants and other debris. By providing a dust cap and anassociated method for testing the continuity of an optical fiber jumperwithout having to remove the dust caps, the resulting performance of theoptical fiber jumper should be improved since the polished front facesof the ferrules will generally have fewer contaminants and other debristhan conventional ferrules.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a dust cap according to one embodimentof the present invention that illustrates an end member having a lens.

FIG. 2 is a perspective view of a dust cap according to one embodimentof the present invention that partially illustrates the bore defined bythe sleeve of the dust cap.

FIG. 3 is a cross-sectional perspective view of the dust cap of FIGS. 1and 2 depicting the bore defined by the sleeve of the dust cap in moredetail.

FIG. 4 is a schematic representation of the operations performed tocheck the continuity of an optical fiber jumper according to oneembodiment of the present invention.

FIG. 5 is a cross-sectional view of the dust cap mounted on arepresentative fiber optic connector.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers-refer to like elements throughout.

Referring now to FIG. 1, the dust cap 10 according to one embodiment ofthe present invention is depicted. As described in more detail below,the dust cap is designed to be mounted upon a ferrule in order toprotect the front face of the ferrule from contaminants and otherdebris. The dust cap includes a sleeve 12 that extends lengthwisebetween opposed first and second ends 14, 16. While the sleeve isdepicted to have a generally cylindrical outer surface, the sleeve canbe shaped differently as long as the sleeve does not interfere with themounting of the dust cap upon the ferrule. As depicted in more detail inFIGS. 2 and 3, the sleeve defines a lengthwise extending bore 18 thatopens through the first end for receiving at least a portion of theferrule.

The dust cap 10 also includes an end member 20 for closing the secondend 16 of the sleeve 12. While the end member and the sleeve can bediscrete components, the end member and the sleeve are typicallyintegrally formed, such as by molding. According to one advantageousaspect of the present invention, at least the end member is translucentsuch that optical signals can be transmitted therethrough. Although theend member can be formed of a variety of materials having differentoptical transmissivities, the end member is preferably formed of amaterial that is relatively optically clear. In one embodiment, forexample, the end member is formed of nylon 12 that is optically clearand that does not allow as much plasticizer to bleed off as does thematerial from which conventional dust caps are formed. Nylon 12 iscommercially available as TR90 Grilamid by EMS-Chemie, Inc., of Sumter,S.C. However, the end member can be formed of other optically clearmaterials. In addition, air is preferably vented during the moldingprocess to reduce the amount of air that is trapped inside of the bore18 by the mold pin that defines the bore since this air may createbubbles in the resulting dust cap, which can somewhat impair the opticaltransmissivity of the dust cap. Although the optical signals transmittedthrough the dust cap are transmitted through the end member as describedbelow, the entire dust cap including the sleeve and the end member canbe integrally formed from the same translucent material, such as nylon12, if so desired. In this regard, not only is nylon 12 optically clear,but nylon 12 is relatively hard and does not shrink much following themolding process such that the resulting dimensions of the dust cap,including the diameter and length of the bore defined by the sleeve, canbe precisely and consistently defined.

In order to improve the optical transmission, the end member 20 of thedust cap 10 can include a lens 22. Typically, the lens is integral withthe remainder of the end member and is formed of the same material, suchas nylon 12. However, the lens is shaped so as to focus incoming opticalsignals and to expand outgoing optical signals, as described below. Inone advantageous embodiment, the lens is a planoconvex lens proximatethe outer surface of the end member. While the inner surface of the endmember can be flat or planar, the end member can also include an innerlens, also typically a planoconvex lens, as depicted in FIG. 3. As alsoillustrated, the outer lens preferably has a diameter that exceeds thediameter of that portion of the bore 18 proximate the second end 16 ofthe sleeve to insure that the outer lens effectively collects theincoming and outgoing optical signals. For example, the outer lens cancover the entire outer surface of the end member, if so desired. Thelens can be designed to have any desired optical characteristics,including any desired magnification and focal length.

In one embodiment, however, the outer lens has a magnification of 2× anda focal length that coincides with the front face of the ferrule asdescribed in more detail below.

Although the end member 20 can have the same size and shape as thesleeve 12, the end member is typically larger in radial cross-section.Although the end members is shown to be substantially cylindrical inshape, a variety of shapes is possible. An appropriately shaped endmember can be easily grasped during the process of assembling andmounting a fiber optic connector. For example, the enlarged end membershown in the figures can be readily engaged by a pick and place machineduring an automated connector assembly process.

In order to insure that the front face of the ferrule is appropriatelyspaced from the second end 16 of the sleeve 12 and, more particularly,from the lens 22, the sleeve can define an internal chamfer 24 forengaging the ferrule. As depicted in FIGS. 3 and 5, for example, themedial portion of the sleeve can define an internal chamfer that extendsradially inward. In one embodiment, the internal chamfer also extends inan axial direction such that the chamfer is disposed at an angle, suchas 30 degrees, relative to the longitudinal axis defined by the bore 18.As illustrated in FIG. 3, the portion of the bore extending between thefirst end 14 of the sleeve and the internal chamfer typically has alarger diameter than the portion of the bore extending between theinternal chamfer and the second end of the sleeve. In this regard, thefirst portion of the bore generally has the same shape as the portion ofthe ferrule upon which the dust cap 10 will be mounted. In addition, thefirst portion of the bore is preferably sized to have either the samesize or, more typically, to be slightly larger than the portion of theferrule upon which the dust cap will be mounted. In the illustratedembodiment, for example, the first portion of the bore is cylindricaland has a diameter that is slightly larger (about 0.2 mm) than thediameter of the bore at the internal chamfer. In contrast, the secondportion of the bore can have a variety of shapes and sizes since theferrule will not extend for any great length therethrough. For example,the second portion of the bore can be frustoconical so as to expand indiameter from the internal chamfer toward the second end of the sleevein order to facilitate optical communications via the lens. Typically,however, the second portion of the bore is sized somewhat smaller thanthe first portion of the bore and has the same general shape as thefirst portion of the bore, such as a cylindrical shape as depicted inFIGS. 3 and 5. Since the front face of the ferrule will be inserted intothe second portion of the bore, the second portion of the bore ispreferably sized to be equal in size or slightly larger than the frontface of the ferrule. See FIG. 5.

FIG. 5 illustrates in cross section, an SC connector with the dust cap10 mounted upon a ferrule 40. The front face 49 of the ferrule isinserted into the first end 14 of the sleeve 12 and dust cap is advancedover the ferrule. The dust cap is typically slid over the ferrule untilthe ferrule or, as shown in FIG. 5, the ferrule chamfer 42 contacts theinternal chamfer 24 of the dust cap. The dust cap, while shown as beingdesigned to be mounted upon the cylindrical SC ferrule where the frontface of the ferrule is slightly smaller in cross section than the shankof the ferrule, the dust cap can be designed to be mounted upon avariety of ferrules. Once the dust cap is properly seated upon theferrule, the front face 44 of the ferrule, including the ends of theoptical fibers (not shown) upon which the ferrule is mounted, isdisposed within the second portion of the bore.

In order to facilitate the mounting of the dust cap 10 upon the ferrule,the first end 14 of the sleeve 12 can also include a chamfered lead insurface 26. In addition, the sleeve can define a groove 28 that extendslengthwise through only a portion of the bore 18. In this regard, thesleeve is preferably designed such that the groove extends from thefirst end to a medial portion of the sleeve with the medial portion ofthe sleeve being selected such that the front face of the ferrule isbeyond the medial portion of the sleeve, i.e., is closer to the secondend 16 of the sleeve, once the dust cap is fully mounted upon theferrule. In the illustrated embodiment in FIG. 3, for example, thegroove extends from the first end of the sleeve to the internal chamfer24. As such, the groove serves to vent air from within the bore as thedust cap is slideably advanced over the ferrule. Thus, the dust cap canbe more easily mounted upon the ferrule. Once the dust cap is fullymounted upon the ferrule (as shown in FIG. 5), such as upon contact ofthe ferrule, and specifically the ferrule chamfer, with the internalchamfer of the sleeve, the front face of the ferrule is isolated fromthe groove, such as by a seal formed between the ferrule or ferrulechamfer and the internal chamfer of the sleeve. Thus, contaminants andother debris that may enter the groove cannot be deposited upon thefront face of the ferrule.

Typically, the internal chamfer 24 is spaced apart from the second end16 of the sleeve 12 by a distance sufficient to prevent any contaminantsand other debris on the second end of the sleeve from being transferredto the front face of the ferrule. For those embodiments of the dust cap10 that include a lens 22, the spacing between the internal chamfer andthe lens is also preferably selected such that the resulting axialseparation between the front face of the ferrule and the lensapproximately equals the focal length of the lens or lens combination.As such, the dust cap can effectively support optical communicationswith the optical fiber upon which the ferrule is mounted.

The dust cap 10 of the present invention is therefore designed toprotect the front face of the ferrule upon which the dust cap is mountedfrom contaminants and other debris. In this regard, the dust cap isdesigned such that the internal chamfer 24 engages the ferrule in orderto space the front face of the ferrule from the closed second end 16 ofthe dust cap by a distance sufficient to prevent the transfer of anycontaminants and other debris from the closed second end to the frontface of the ferrule. In addition, the dust cap is designed such thatonce the dust cap is fully mounted upon the ferrule, the front face ofthe ferrule is isolated from the groove 28 that facilitates venting ofthe air from within the bore during the mounting of the dust cap uponthe ferrule, thereby preventing contaminants and other debris that mightenter the groove from ever being deposited upon the front face of theferrule. Since at least the end member 20 of the dust cap is translucentand, in some embodiments, includes a lens 22, the dust cap of thepresent invention supports optical communications with the optical fiberupon which the ferrule is mounted while the dust cap remains mountedupon the ferrule. By way of illustration, a method of testing thecontinuity of an optical fiber jumper 30 according to another aspect ofthe present invention is hereinafter described.

As described above, optical fiber jumpers 30 must generally be checkedfor continuity immediately prior to packing and shipping the opticalfiber jumpers to minimize the number of defective jumpers that aredelivered to a customer. In this regard, an optical fiber jumpertypically includes at least one optical fiber 32 and first and secondfiber optic connectors 34 mounted upon the opposed ends of the at leastone optical fiber. The optical fiber jumper also includes first andsecond dust caps 10 that are mounted upon the ferrules of the first andsecond fiber optic connectors, respectively. Prior to packing theoptical fiber jumper, a light source 36 can be positioned adjacent theend of the optical fiber jumper upon which the first fiber opticconnector is mounted so as to introduce signals through the dust cap tothe at least one optical fiber upon which the first fiber opticconnector is mounted. Additionally, a detector 38, such as aphotodetector, can be positioned proximate the other end of the opticalfiber jumper upon which the second fiber optic connector is mounted inorder to detect the optical signals emitted by the at least one opticalfiber upon which the second fiber optic connector is mounted.

According to this aspect of the present invention, the dust caps 10remain mounted upon the ferrules of the first and second fiber opticconnectors 34 while the optical signals are introduced into and emittedfrom the optical fibers 32. In fact, in those embodiments in which thedust caps include a lens 22, the lens of the dust cap mounted upon theferrule of the first fiber optic connector actually serves to focus theincident light upon the end of the optical fibers upon which the ferruleis mounted. Likewise, the lens of the dust cap mounted upon the ferruleof the second fiber optic connector serves to expand the light emittedby the optical fibers upon which the second fiber optic connector ismounted in order to facilitate the subsequent detection of the opticalsignals by the detector 38.

By permitting the continuity of the optical fiber jumper 30 to bechecked without removing the dust caps 10 from the ferrules of the fiberoptic connectors 34, the method of this aspect of the present inventionprevents any additional contaminants and other debris from beingdeposited upon the front face of the ferrules, the likelihood of whichwould be increased as a result of the electrical charging of theferrules that would occur if the dust caps were slideably removed fromthe ferrules. In addition, the method of this aspect of the inventionalso simplifies the continuity test somewhat by not requiring theoperator to remove and subsequently replace the dust caps on both endsof the optical fiber jumper.

Accordingly, the dust cap 10 of the present invention protects thecleanliness of the front face of the ferrule by preventing contaminantsand other debris from being deposited upon the front face of the ferrulefollowing its polishing. In particular, the dust caps can be designed tobe transparent such that the dust caps can remain mounted upon theferrules of the respective fiber optic connectors 34 as the continuityof an optical fiber jumper 30 is tested. In addition, the dust caps caninclude lenses 22 that further facilitate continuity testing by focusingthe incident light upon the optical fibers and by expanding the lightemitted by the optical fibers. By reducing the amount of contaminantsand other debris that are deposited on the front face of the ferrules,the dust cap of the present invention therefore helps to improve theperformance of the optical system in which the optical fibers, such asthe optical fiber jumpers, are eventually installed since thecontaminants and other debris would otherwise degrade the systemperformance.

Many modifications and other embodiments of the invention will come tomind to one skilled in the art to which this invention pertains havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. Therefore, it is to be understood that theinvention is not to be limited to the specific embodiments disclosed andthat modifications and other embodiments are intended to be includedwithin the scope of the appended claims. Although specific terms areemployed herein, they are used in a generic and descriptive sense onlyand not for purposes of limitation.

That which is claimed:
 1. A method for testing continuity of an opticalfiber jumper, the method comprising: providing the optical fiber jumpercomprising at least one optical fiber, first and second fiber opticconnectors including respective ferrules mounted upon opposed ends ofsaid at least one optical fiber, and at least one dust cap having atranslucent end member mounted upon a respective ferrule; introducinglight into one end of the at least one optical fiber; and monitoring thelight emitted by the other end of the at least one optical fiber tothereby check the continuity of the optical fiber jumper, wherein saidintroducing and monitoring are performed while the at least one dust capis mounted upon the respective ferrule.
 2. A method according to claim 1wherein providing the optical fiber jumper comprises providing anoptical fiber jumper having first and second dust caps with translucentend members mounted upon the ferrules of the first and second fiberoptic connectors, respectively.
 3. A method according to claim 2 whereinthe end member of each dust cap comprises a lens, and whereinintroducing light comprises focusing light into one end of the at leastone optical fiber.
 4. A method according to claim 2 wherein the endmember of each dust cap comprises a lens, and wherein monitoring theemitted light comprises expanding the light emitted by the other end ofthe at least one optical fiber.